These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Anvilicious: The main human ship is called the Ark, and the smaller ships are shaped like crosses. Subtle.
Considering the Big Bad quotes the Bible multiple times in the movie, I think they weren't necessarily going for subtle. And really, the Cross shaped fighters look more like B-Wings than the Traditional Christian Cross.
The whole Anti-war/Tolerance message of this film wasn't very subtle, anyway.
More subtle than you give it credit for. The story of a peace-loving people repelling an alien incursion through force of arms is more Jack Nicholson's "you need me on that wall" speech with better PR than it is a pure anti-war message.
Just going along with the "ships-as-crosses" bit, it does feel anvilicious at the start where the Terrians "give themselves up to the ships." (If you don't get it, just replace the word "ships" on that phrase with the word "cross.")
How do you really drive home an anti-war message in the anvilliest way? By having three whole planets blown up in the backstory.
Going further, the film has (human) male nudity (not frontal, but still), several dead (alien) bodies on slabs and hanging in body bags in the worst abattoir-like display possible. And to top it off the on-screen deaths by decompression of no less than four people, one of whom was a protagonist's father, and another was Jim.